Historically, people first wore shoes to protect their feet. Over the centuries, footwear evolved into many different types that were specific to particular activities. Thus, the protection offered by a cold-weather work boot is highly different from that offered by a running shoe. In addition to protecting the feet, athletic footwear has further developed to offer specific functions dependent on the particular sport. Soccer shoes, for instance, have spikes for traction, whereas cycling shoes have very stiff soles with mounting plates for cleats to engage the pedal.
The game of golf includes long stretches of walking and short moments of swinging a golf club to hit a golf ball. Consequently, golf shoes have evolved to provide the wearer with good traction on grass, comfort while walking, and a stable platform for hitting the ball. Typical golf shoes thus have a relatively stiff sole with metal spikes or plastic cleats. Some golf shoes also include gels that cushion the impact of so-called “ground reaction forces” on the foot. From Newton's Third Law of Motion, the law of action-reaction, it is known that the ground pushes on the foot in a direction equal and opposite to the direction the foot pushes on the ground; these are known as ground reaction forces.
Gels have been incorporated into the sole of athletic shoes. Conventional gels are generally pre-set to fit the contours of a foot or they are soft liquid gels that must be placed in a bladder. Some examples include U.S. Pat. Nos. 5,155,927 and 5,493,792 to Bates, which disclose athletic shoes constructed to minimize impact shock and maximize lateral stability by use of a cushioning element comprising a chamber having flexible walls filled with a liquid composition which is preferably a gel and the chamber has a plurality of partitions for directing the flow of liquid from one portion of the chamber to another.
However, there remains a need in the art for golf shoes having collapsible support elements that minimize the impact of ground reaction forces when walking, and that allow more efficient transfer of energy during a golf swing.